Evaluating the Association of the Increase in the WIC Cash Value Benefit on the Diversity of MyPlate Fruits and Vegetables Redeemed and Consumed By Children in Low-Income Households

Background Fruits and vegetables (FV) are a critical source of nutrients, yet children in the United States are not meeting the Dietary Guidelines for Americans (DGA). The monthly FV cash value benefit (CVB) included in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)’s food package to support child FV intake (FVI) received a substantial increase for economic relief during the COVID-19 pandemic. Objectives To evaluate how an expansion of the monthly WIC CVB to purchase FV for WIC children ages 1–4 y is associated with diversity in FV redeemed, and how changes in redeemed FV are related to FVI. Methods Caregivers representing 1463 WIC-participating children recruited from Los Angeles County, California, completed surveys during the CVB augmentation (T1: CVB = $9/mo; T2 = $35/mo; T3 = $24/mo). Redeemed price look-up codes (PLUs), corresponding to a food item, were assigned to its corresponding MyPlate FV group. Multivariable generalized estimating equation regression models assessed changes in amount and diversity of FV redemption across MyPlate groups and associations between changes in FV diversity and changes in FVI. Results Slightly over half of all households were food insecure (55%), half of the children were female (52%), and most were Hispanic (78%). Compared with T1, significant increases in the number of PLUs and dollars redeemed were observed in most MyPlate FV groups. From T1 to T2, significant increases in diversity scores were observed for total fruit (β: 1.6 pts; 95% confidence interval [CI]: 1.4, 1.7), total vegetable (β: 3.6 pts; 95%CI: 3.4, 3.9), and total FV (β:7.8 pts; 95%CI: 7.4, 8.2). Similarly, increases in diversity score were observed at T3 compared with T1. Changes in FV diversity redeemed were not associated with changes in FVI. Conclusions During the CVB augmentation, WIC participants redeemed a greater amount and variety of FV according to DGA MyPlate recommendations, supporting its permanent increase.


Introduction
Adequate diet quality in childhood is fundamental for maintaining physical health and establishing strong dietary habits that are likely to be tracked into adulthood [1,2].Childhood is a period of rapid growth, and fruits and vegetables (FV) provide a significant source of nutrients for optimal growth [3,4].Poor nutrition habits in young children have been associated with markers of obesity, dyslipidemia, and hypertension that persist throughout adulthood [5][6][7].In addition to the amount of FV consumed, the diversity of FV selection has been positively associated with aspects of nutritional intake, such as increased vitamin and fiber consumption in adolescents [8].Eating more types of FV has been associated with higher Healthy Eating Index-2010 (HEI-2010) scores in preschool-aged children from the 2005 to 2010 National Health and Nutrition Examination Survey [9].In a sample of Texan 8th and 11th-graders, higher intake of fruit, vegetable, and combined FV diversity showed a similar pattern of higher HEI scores [10].Furthermore, selecting a diversity of FV has been associated with eating a higher quantity of FV [11].
Although quantity and diversity of FV consumption plays an essential role in nutritional intake, 2-to 4-y-old children are not meeting recommendations set by the 2020-2025 Dietary Guidelines for Americans (DGAs) [12].On average, children aged 2-4 y are eating <1 cup of total vegetables compared with the recommended 1-2 cups per day [12].This shortfall from recommendations is even more pronounced for dark green, red, and orange vegetables [12].Moreover, income and racial and ethnic disparities in fruit and vegetable intake (FVI) exist among youth.From 2015 to 2018, fruit and dark green vegetable consumption was significantly lower among children and adolescents aged 2-19 y in lower-income households in the United States [13].In 2021, non-Hispanic (NH) Blacks had the highest percentage of children aged 1-5 y not meeting daily fruit (51%) and vegetable (65%) recommendations compared with NH White children not meeting daily fruit (26%) and vegetable (43%) recommendations [14].Likewise, there were higher percentages of Asian children (fruit: 42%; vegetables: 48%) and Hispanic children (fruit: 34%; vegetable: 54%) also not meeting daily recommendations as compared with NH whites [14].
To address disparities in diet quality, the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides a food package and nutrition education that promotes FVI for low-income, nutritionally at-risk families [15].The food package includes a monthly cash value benefit (CVB) that can be used to purchase fruits and vegetables, in addition to juice, milk, cereal, cheese, eggs, whole-wheat bread, fish, and legumes [16].The CVB is unique from other items in the food package as it maximizes WIC participant autonomy, enabling households to purchase diverse selections of FV.
During the COVID-19 pandemic [17], a period that magnified food insecurity disparities, [18][19][20][21] WIC increased the CVB for children aged 1-4 y from $9 per month to $35 per month in June 2021, which was revised to $24 in October 2021 [22,23].A qualitative study of 51 WIC participants in Delaware showed that the increase in the CVB allotment allowed an increase in the amount and variety of FV redeemed [24].WIC families' perceptions of the CVB increase have also been positive, as they felt their children gained increased access to a variety of FV [25][26][27].In low-income and racial and ethnically diverse households, a higher amount of CVB bolstered FV consumption, trips to the grocery store, and increased dietary variety [24].At the increased amount, the CVB is aligned with National Academies of Sciences, Engineering, and Medicine recommendations, which ensures that the WIC CVB provides enough money to support 50% of the child FVI recommended in the DGAs [28].Additionally, the USDA has recently announced that the WIC CVB will remain at the increased amount permanently to support its alignment with federal guidelines [29].
Previous studies have focused on qualitative results related to the CVB increase and perceived increases in FVI [24][25][26][27].However, very few studies have quantitatively examined how the increase in CVB influenced the variety of FV redeemed and consumed in children.Thus, the objective of this study is to evaluate whether the expansion of the monthly WIC CVB for the purchase of FV among children is associated with diversity in FV redeemed, and how the diversity of FV redeemed is related to child FVI in a California WIC sample.The hypothesis is that increasing the WIC CVB for a 1-y period will increase the diversity of FV redeemed, and the increase in diversity of FV redemption will be associated with increased FVI in children.

Child FVI
At each survey time point caregivers were asked to report children's FVI using the National Health and Nutrition Examination Survey (NHANES) Dietary Screener Questionnaire (DSQ) [30].Reported frequencies were used to estimate quantities of FVI (cups/day) using the publicly available National Cancer Institute-generated scoring algorithms by child age and gender.Total FVI included legumes, 100% fruit juice, and fried potatoes [31].This method has been validated for use in studies with limited data [32] to evaluate child FVI [33][34][35].

Redemption data
From June 2020 to June 2022, monthly CVB redemption data were collected on all participants.Redemption data are captured at the household level, meaning that families with >1 individual participating in WIC have a total CVB redemption amount combined from all WIC participants in that household.CVB redemption was averaged across 3 mo before each survey time point (T1: February-April 2021, T2: June-August 2021, and T3: February-April 2022).Therefore, this analysis only included participants who had redemption data 3 mo before each survey time point for a total sample of n ¼ 1463.Redemption data were categorized by MyPlate groups [36] by sorting redeemed PLUs into berries, melons, other fruits, dark green vegetables, red/orange vegetables, beans/peas/lentils, starchy vegetables, and other vegetables (Supplemental Table 1).Using MyPlate, CVB redeemed was assessed by dollars (USD) redeemed, number of PLUs redeemed, and percent of monthly CVB redeemed.

Diversity scores
The diversity scoring method used was adapted from Anderson et al. [37], which was developed encompassing concepts of disparity, variety, and balance [38].Fruit, vegetable, and total FV diversity scores were calculated using the percent of CVB redeemed in each MyPlate group.MyPlate groups were used for fruits (consisting of 3 categories: berries, melons, and other fruits) and vegetables (consisting of 5 categories: dark green, starchy, beans/peas/lentils, red and orange, and other vegetables) equaling 8 total categories for FV [36] Assuming perfectly balanced redemption among groups, fruit redemption would be 33.3% in each group (i.e., 100/3 ¼ 33.3%; and for vegetables 20% in each group, and for total fruits and vegetables 12.5% in each group).A fruit diversity score was calculated by first subtracting the percentage of CVB redemption in that commodity group from 33.3%.Then taking the absolute value of this difference and adding 10% (to ensure that the maximum contribution of any single category is truncated at 10 points).Truncation at a maximum of 10 points per MyPlate group was chosen to ensure that redemption in 1 MyPlate group would not overwhelm the variety of redemption observed in the other MyPlate groups.Then the inverse of this value was taken.Lastly, the overall fruit diversity score was determined by summing across all 3 fruit groups.The same process was repeated for the vegetable and FV scores using their perfect balanced redemption percentage in step 1 and summing across their total number of categories for overall diversity score (i.e., for vegetables using 20% in step 1 and summing across 5 groups).A higher diversity score indicates redemption in a greater number of groups and a greater balance of redemption among the different MyPlate groups.

Covariates
Covariates included in regression models were selected based on previously reported associations with either redemption or FVI, or both, and which were thought to represent potential confounding factors.The demographics of the participants included variables such as race, age, and number of children within the household.Household food security was assessed within each survey using the validated USDA 6-item Food Security Survey module [39].In previous studies on low-income children this tool has been shown to capture HFS for the 30 d before the survey [33].

Statistical analysis
Children's characteristics were summarized using frequencies and percentages for categorical variables.Continuous variables were described using means and standard deviations (SDs).Multivariable generalized estimating equation (GEE) regression models were used to test associations between the time period for the CVB augmentation and each redemption outcome, expressed as estimates and 95% confidence intervals (CIs; in My Plate groups for dollars, PLUs, and percentage and diversity scores).
Linear GEE models were also used to evaluate associations between change in diversity score and change in child intake (cups/day) (e.g., fruit diversity with fruit intake).In the original longitudinal cohort, increases in FVI were only observed among children not meeting FVI recommendations at baseline (<1.5 cups/d) [23].Additional analyses were conducted to test for effect modification of the association between diversity scores and FVI by child baseline FVI at 3 levels: <1.5 cups/d, 1.5 to <2.5 cups/d, and !2.5 cups/d).Effect modification was also investigated for associations with number of children in the household, race and ethnicity, and HFS status.All models were adjusted for child race, gender, age at baseline, HFS status, and number of children in the household under age 18 y.

Discussion
In this longitudinal study of critical public health investment, WIC-participating households purchased greater amounts and diversity of MyPlate FV during the increased CVB.Additionally, households were able to purchase more MyPlate vegetables such as red/orange, other, and starchy vegetables (e.g., corn, yams, green lima beans) that children are currently underconsuming [12].Consuming a greater variety of FV is essential, especially during childhood as it has been associated with increased diet quality [9], meeting nutrient needs, and reducing the risk of diet-related diseases [40].These findings are noteworthy as this study was conducted within a low-income population who often purchase foods of lower nutritional quality [41] and consume lower amounts [42] and variety [43] of FV.Furthermore, current literature shows that dietary habits established early in childhood persist throughout the lifespan [2,44,45].As research has shown that utilizing MyPlate can improve diet quality [46,47] understanding the redemption of MyPlate food groups may support WIC staff in encouraging participants to consume FV in alignment with dietary guidance.
Significant increases for number of PLUs and dollars redeemed were observed in most of the MyPlate groups at T2 and T3 when comparing with T1.This is consistent with previous research as WIC-participating households redeemed significantly more money for the majority of FV PLU-group PLUs during the CVB augmentation [37].The lack of change among percentage of CVB redeemed among foods has also been documented in previous literature [37].Beans, peas, and lentils were the only MyPlate group with no consistent significant changes in the number of PLUs and the number of dollars redeemed from T3 compared with T1, with the monetary difference being very small at ~$0.01.This nonsignificant difference may be due to beans being provided in the CA WIC package separately from the CVB [48].Households also purchased a greater diversity of FV, as total fruit, vegetable, and FV diversity scores increased in both T2 and T3 compared with T1.This was also observed in previous studies where WIC participants expressed how they were able to redeem a greater variety of FV for their families due to the increased CVB amounts [24,27].
This study is unique as it investigates the variety of FV redeemed during the CVB increase and its association with child FVI.This analysis found no significant associations of FV variety redeemed with child FVI.In the study by Whaley et al. [23] using a similar population, FVI increased during the CVB augmentation among children with lower baseline FVI, and the greatest increase was observed among children with a baseline <1.5 cups/d.However, in this study, no association was observed between change in FV diversity redeemed with any diversity score (e.g., fruit, vegetable, or FV) from baseline and change in FVI from baseline at either time point (T2 or T3).This diversity of findings suggests that increases in diversity of purchases, rather than total purchases, may have differential associations with FVI.The augmented CVB value is estimated to only support ~50% of a child's FV recommendation [28], and therefore changes to diversity of purchases may not be of sufficient magnitude to detect differences in child FVI.Additionally, findings may reflect a spillover effect where other members of the household that are non-WIC participants may benefit by also consuming the increased diversity of the FV redeemed [49,50].
Strengths of this study include a large sample size with detailed redemption data down to the level of PLUs, allowing examination of the specific types of FV redeemed.Furthermore, the diverse population of Southern California allows the opportunity to understand how WIC changes impacted households from several racial and ethnic backgrounds.However, limitations within this study also exist.This study does not account for Abbreviations: CVB, cash value benefit; SD, standard deviation; USD, United States dollar; WIC, the Special Supplemental Nutrition Program for Women, Infants, and Children; PLU, price look-up codes. 1 Denominator N is 1297 households, smaller than the 1463 children, as households could have >1 child enrolled in the study. 2Food security was captured using the USDA 6-item Food Security Survey module.Each affirmative response to the 6-items contributes 1point; scores were dichotomized with those <2 indicating high/marginal household food security (HFS). 3CVB redemption is captured at the household level not at the individual level, therefore CVB redemption value could exceed monthly CVB issued to each child. 4Fruit and vegetable intake included legumes and included fried potatoes and 100% fruit juice. 3Dollar amount is expressed as the mean (standard deviation) amount of cash value benefit (CVB) redeemed per family (USD) in the specified category during the 3 CVB amounts issued (T1: 9 USD/mo; T2: 35 USD/mo; T3: 24 USD/mo) during the study period. 4Percentage of CVB is expressed as the percentage of 3 prior months where there was any redemption in the specified category during the study period. 5Fruit diversity was captured as the sum (across all 3 MyPlate fruit groups) of the inverse of the absolute value of 33.3 minus the percent of redemption of fruits plus 10 [i.e., 1/(absolute value (33.3 À percent in specific category)þ10)]. 6Vegetable diversity was captured as the sum (across all 5 MyPlate vegetable groups) of the inverse of the absolute value of 20.0 minus the percent of redemption of vegetables plus 10 [i.e., 1/(absolute value(20.0À percentage in specific category)þ10)]. 7Total FV diversity score was captured as the sum (across all 8 MyPlate groups) of the inverse of the absolute value of 12.  [40].Vegetable intake is shown to decrease as children age [40], however, this study was unable to account for this by control group comparison because the CVB augmentation was implemented nationally.Lastly, the results of this study may not be generalizable to other states, as California has higher FVI than national FVI levels [52,53], emphasizing the need for additional research from a nationally representative sample.
In conclusion, WIC participants redeemed a greater amount and variety of FV during the CVB augmentation, adding to the evidence that supported the need for the increased CVB amount.Although further research is needed to understand how these changes impact child FVI among WIC participants nationwide, this study demonstrates that participating households utilized additional FV benefits for a broad diversity of FV, potentially improving nutritional outcomes.Lastly, this participant-focused change helped to address nutritional gaps that were highlighted during the COVID-19 pandemic, strengthening the WIC program.

TABLE 3
Adjusted association of change in diversity of fruit and vegetable score on fruit and vegetable intake in WIC-participating households in Southern California during augmentation of the CVB for fruits and vegetables (n ¼ 1173) 1   Association with change in child dietary intake 2   Change in diversity score 3  Fruit intake, cups/d Vegetable intake 4  Abbreviations: CVB, cash value benefit; USD, United States dollars; SD, standard deviation; WIC, the Special Supplemental Nutrition Program for Women, Infants, and Children; FV, fruit and vegetables. 1 Sample size ranges from 727-1,173 due to the number of completed surveys at each timepoint. 2Estimate (95% confidence interval) for child dietary intake associations was determined for T2 (35 USD/mo) and T3 (24 USD/mo) compared to T1 (9 USD/mo) in generalized estimating equations linear regression adjusted for child race/ethnicity, sex, and age; household food insecurity and the number of household members under age 18; Models also accommodated clustering of observations within participating children and families. 3Change in diversity was calculated as fruit, vegetable, and FV diversity score at time period 2 minus time period 1, and time period 3 minus time period 1, respectively. 4Vegetable intake and FV intake included legumes, fried potatoes, and 100% fruit juice.

TABLE 1
Characteristics of WIC-participating Southern California children included in the study

TABLE 2
Change in number of PLUs redeemed, dollars redeemed, and percentage of CVB redeemed in MyPlate fruit, and vegetable groups by WICparticipating households in Southern California during augmentation of the CVB for fruits and vegetables, June 2020-June 2022 (n ¼ 1463) PLU redemption is expressed as the mean (standard deviation) number of PLUs redeemed per family in the specified category.2Estimate (95% confidence interval) for each redemption outcome was determined for T2 (35 USD/mo) and T3 (24 USD/mo) compared with T1 (9 USD/mo) in generalized estimating equations linear regression models adjusted for child race/ethnicity, gender, and age; household food insecurity and the number of household members under age 18 y.Models also accommodated clustering of observations within participating children and families. 1 , cups/d Fruit and vegetable intake4, cups/d